Quote Originally Posted by chem geek

By the way, how in the heck did you ever get your pool water's CH to 990? Did you add tons of calcium chloride pellets at some point?

Richard
I wish I knew for sure how it got so high. I suppose the test could be in error. I followed the Taylor instructions to the "T". To avoid false readings (due to fading endpoint) I added five drops of titrant (hardness reagent) to the sample first and then continued the test as usual. At 99 drops the sample finally turned blue. Next time I check it I'll follow the procedure for high CH (smaller sample, less drops, multiply by 25).